tailieunhanh - Biofuels, Solar and Wind as Renewable Energy Systems_Benefits and Risks Episode 2 Part 6

Tham khảo tài liệu 'biofuels, solar and wind as renewable energy systems_benefits and risks episode 2 part 6', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 364 D. Pimentel . Patzek petroleum used in the . was about 1 200 billion liters in 2004-2005 USCB 20042005 . To produce the billion liters of ethanol about million ha or 20 of . corn land is used. Furthermore the billion liters of ethanol energy equivalent to billion liters of vehicle liquid fuel provides only 1 of the petroleum utilized by . each year. If corn-ethanol production were expanded to using 100 of . corn production this would provide only 7 of the petroleum needs Ethanol Production and Use in Brazil In contrast Brazil can fuel most of its automobiles and other vehicles with ethanol because Brazilians consume only 9 of the . consumption in petroleum BP 2005 . Since 1984 the portion of Brazilian sugarcane used for ethanol decreased from a peak of 70 to about 55 in 2000 Schmitz et al. 2003 . During that time the percentage of ethanol cars declined from 94 in 1984 to less than 1 in 1996 Rosillo-Calle and Cortez 1998 . The difference included gasoline for the cars. Flex cars replaced the ethanol cars and as a result Brazil s oil consumption has increased 42 during the last decade BP 2001 2005 . Proponents of ethanol point to the production of ethanol in Brazil but ignore the fact that the . now produces more ethanol billion liters ethanol per year compared with Brazil that produces about billion liters per year Calibre 2006 . Brazil is fortunate to have the land and climate suitable for sugarcane. Sugarcane is a more efficient feedstock for ethanol production than corn grain Patzek and Pimentel 2005 . However because Brazilian energy balance is only slightly positive 1 kcal kcal the Brazilians need to heavily subsidize their ethanol industry as does the . In the 1980s and 1990s the Brazilian government sold ethanol to the public for 22 c per liter but it cost the government 33 c per liter to produce Pimentel 2003 . Because other priorities emerged in Brazil the government has since abandoned .